Weasels?

Something has been getting into the coop at night and killing my neighbor's chickens. The chickens are not eaten except that one or two were missing their heads. The rest of them were just dead and untouched. He thought at first it was a raccoon but the only opening into the hen house is a very small space up under the eaves. Not more than two or three inches. And if it is a weasel, how do you trap it? He has traps set around outside the coop but so far the only thing he has caught was a rabbit. Tonight he put a light in the hen house in the hope that maybe if the light was on the predator would stay away. Any ideas? Suggestions? Anything?

You're probably right. Funny thing is he has had chickens in this coop for 20 years without a problem. As for a cat, feral or otherwise, the opening is too small for a cat. And somehow I can't see a small (it would have to be small to squeeze in) cat killing six large hens weighing more than eight pounds apiece in one night. And coming back the next night to kill three more without eating any of them.